‘The Big Bang Theory,’ a Durable Hit for CBS, Will End in 2019

‘The Big Bang Theory,’ a Durable Hit for CBS, Will End in 2019“The Big Bang Theory,” CBS’s enormously successful sitcom, will finish its 12-season run in May, Warner Bros. announced on Wednesday.

The series will clock in at 279 episodes, a total that Warner Bros., which produces the show, said would make it the longest-running multicamera comedy in TV history. “Cheers” had 275 episodes when it ended its storied run on NBC in 1993.

The sitcom, created by Chuck Lorre and Bill Prady and starring Jim Parsons as one of the socially awkward scientists navigating life at a university, debuted in September 2007. Consistently one of the most watched television shows, it has been nominated for 52 Emmy Awards, winning 10. Mr. Parsons, who plays Sheldon Cooper, a brilliant, abrasive and hopelessly dorky physicist, has won the Emmy for best actor in a comedy four times.

The loss of “The Big Bang Theory” will be a major blow to CBS. The show has long been an anchor for the network and is, by far, its highest-rated series in the prized 18-to-49-year-old demographic. With the network’s chief executive, Leslie Moonves, under an internal investigation for past workplace misconduct, the loss of a reliable viewer favorite will only add to the air of uncertainty at the network.

“‘The Big Bang Theory’ has been the defining comedy of its generation,” Kelly Kahl, the president of CBS Entertainment, said in a statement on Wednesday.

In the most recent TV season, the series was the No. 3-rated entertainment network show among adults under 50, behind only “This Is Us” and “Roseanne.”

The end-of-an-era feeling may be even more pronounced once “The Big Bang Theory” signs off. In recent years, few comedies have had the kind of blockbuster ratings success that the show has enjoyed, and many TV executives wonder if any show can ever come close to those heights again.

Newer comedy hits like FX’s “Atlanta” or NBC’s “The Good Place,” while critically lauded and loved by their viewers, draw a fraction of the audience of “The Big Bang Theory.” Last season, “The Big Bang Theory” averaged nearly 15 million viewers a week, compared with the 5.7 million who watched “The Good Place,” according to Nielsen’s delayed-viewing data.

CBS does air a successful spinoff, “Young Sheldon,” about a younger version of the character played by Mr. Parsons growing up in East Texas in the 1980s. “Young Sheldon” rated among the top 10 entertainment shows this season and drew more than 13 million viewers an episode, according to Nielsen’s delayed-viewing data.

But the end of “The Big Bang Theory” has been coming for some time. Shortly before “Young Sheldon” debuted last year, Mr. Parsons — who provides voice-over narration in the spinoff — said he was hopeful that the show would do well so he could keep Sheldon Cooper in his life.

“I know how hard it will be to end this job of playing this character, and this is going to be a nice way for me to deal with it,” Mr. Parsons told The New York Times last year. “Hopefully it won’t feel as much deathlike when that day comes.”

The final season of “The Big Bang Theory” will begin on Sept. 24, a Monday. The show will then take over its regular 8 p.m. slot on Thursdays.